From f1174f77b50c94eecaa658fdc56fa69b421de4b8 Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Mon, 7 Aug 2017 15:26:19 +0100 Subject: bpf/verifier: rework value tracking Unifies adjusted and unadjusted register value types (e.g. FRAME_POINTER is now just a PTR_TO_STACK with zero offset). Tracks value alignment by means of tracking known & unknown bits. This also replaces the 'reg->imm' (leading zero bits) calculations for (what were) UNKNOWN_VALUEs. If pointer leaks are allowed, and adjust_ptr_min_max_vals returns -EACCES, treat the pointer as an unknown scalar and try again, because we might be able to conclude something about the result (e.g. pointer & 0x40 is either 0 or 0x40). Verifier hooks in the netronome/nfp driver were changed to match the new data structures. Signed-off-by: Edward Cree Signed-off-by: David S. Miller --- drivers/net/ethernet/netronome/nfp/bpf/verifier.c | 24 +++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) (limited to 'drivers/net/ethernet') diff --git a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c index d696ba46f70a..5b783a91b115 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c @@ -79,28 +79,32 @@ nfp_bpf_check_exit(struct nfp_prog *nfp_prog, const struct bpf_verifier_env *env) { const struct bpf_reg_state *reg0 = &env->cur_state.regs[0]; + u64 imm; if (nfp_prog->act == NN_ACT_XDP) return 0; - if (reg0->type != CONST_IMM) { - pr_info("unsupported exit state: %d, imm: %llx\n", - reg0->type, reg0->imm); + if (!(reg0->type == SCALAR_VALUE && tnum_is_const(reg0->var_off))) { + char tn_buf[48]; + + tnum_strn(tn_buf, sizeof(tn_buf), reg0->var_off); + pr_info("unsupported exit state: %d, var_off: %s\n", + reg0->type, tn_buf); return -EINVAL; } - if (nfp_prog->act != NN_ACT_DIRECT && - reg0->imm != 0 && (reg0->imm & ~0U) != ~0U) { + imm = reg0->var_off.value; + if (nfp_prog->act != NN_ACT_DIRECT && imm != 0 && (imm & ~0U) != ~0U) { pr_info("unsupported exit state: %d, imm: %llx\n", - reg0->type, reg0->imm); + reg0->type, imm); return -EINVAL; } - if (nfp_prog->act == NN_ACT_DIRECT && reg0->imm <= TC_ACT_REDIRECT && - reg0->imm != TC_ACT_SHOT && reg0->imm != TC_ACT_STOLEN && - reg0->imm != TC_ACT_QUEUED) { + if (nfp_prog->act == NN_ACT_DIRECT && imm <= TC_ACT_REDIRECT && + imm != TC_ACT_SHOT && imm != TC_ACT_STOLEN && + imm != TC_ACT_QUEUED) { pr_info("unsupported exit state: %d, imm: %llx\n", - reg0->type, reg0->imm); + reg0->type, imm); return -EINVAL; } -- cgit v1.2.3